Water has been commonly used as a coolant in dental drilling though, as described in my co-pending application entitled "Liquid Admixing Apparatus for Dental Water-Injection Systems", Ser. No. 752,300 filed July 5, 1985, the addition of flavoring agents or the like to coolant water has been proposed to provide a pleasant taste in the patient's mouth during and after the dental procedure. However, conventional use of water-based coolants does not prevent the formation of microscopic, but nonetheless observable, chipping, ridging and surface cracking of the tooth enamel and dentin from the action of the drill bur. It is the principal purpose of the present invention to improve upon water coolants used during the drilling or cutting of human hard tissue such as tooth enamel so that a cleaner, smoother surface topography results. It is a further and equally important purpose of the present invention to reduce substantially the drilling time required to cut or drill into tissue of a given hardness. All of this is to be achieved by a solution which acts as a coolant, a lubricant and an anti-infection agent and which includes separate components for each of those purposes.